This is a camming pin bearing for the case feed cam and stage assembly that moves your cases from the drop tube and gets them on the rotary shell plate. Instead of grease this part puts a roller bearing on the end of the cam follower in order to have smooth case dropping without grease and eventual wear of the plastic cam.
It is a very simple drop-in upgrade. Unscrew your part and replace with the Dillon Performance Improvements Roller Cam Follower.
The Hit Factor Shooting Camming Pin Bearing makes a marked reduction in friction and drag and is a noticeable difference. There is less jiggle, less effort and less powder spillage.